1. Field of the Invention
The invention relates to railway axles and consists particularly in locking plates for the end cap screws on roller bearing axles.
2. The Prior Art
The prior art includes a locking plate having apertures for three cap screws and formed with a pair of cap screw locking tabs lanced in the material of the plate adjacent each cap screw aperture so as to be bent upwardly and engage different faces of the cap screw head to prevent its turning. Looseness often results with this construction because of the impossibility of maintaining the tabs in tight engagement with the faces of the cap screw heads due to the tendency of the tabs to spring back from the head and also due to the fact that the faces of the cap screw head are frequently not parallel to the tab surface.
Another example of prior art utilizes a locking plate with upstanding tabs engageable with the inner and upper surfaces of the three cap screw heads and secured to the axle end by a hexagonal head grease fitting, the lubricating fitting head being adapted to act through the metal of the locking plate to force the tabs into overlying and abutting engagement with the three cap screw heads.
In another embodiment of the same invention the locking plate is formed with three wedge-shaped arms having serrated edges engageable with faces or angles of the cap screw heads to prevent their rotation.
A third embodiment of the same invention includes a combination of radial arms and radial tabs having flat upright surfaces centrally indented for engagement with either faces or angles of the cap screw heads.
Another example of prior art utilizes a pair of plates one of which is formed with three circular apertures to receive the shanks of the cap screws and the second of which is formed with three serrated generally circular apertures the serrations of which are adapted to engage faces and angles of the cap screws and prevent their rotation. The first plate is secured to the axle cap by means of the cap screw heads which overlie it and is formed with three outwardly projecting tabs bendable over the second plate to retain the second plate in locking position.
A further example of prior art shows a locking plate having suitably spaced circular apertures to receive the shanks of the cap screws with the middle of the locking plate being removed and there being a pair of tabs extending inwardly from the regions surrounding each cap screw aperture and bendable upwardly to engage faces of the cap screw. This construction, like the first-named construction, has the disadvantage that it is impossible to maintain the tabs in tight engagement with the cap screw faces.
In yet another example of prior art, individual locking plates for each cap screw are superimposed upon the plate described immediately previously and are held thereon by rebending the tabs flat into engagement with the rim of the individual plates and the individual plates are partly serrated for engagement with the cap screw head faces and angles and are formed with a tail portion engageable with the axle cap rim to prevent loosening rotation of the individual cap screws.